Automotive rear view mirrors are well known, easy to use, and effective, but they have some undesirable characteristics. Mirrors mounted inside automobiles typically have a limited field of view, leaving "blind spots" along the sides of the vehicle. Mirrors mounted outside automobiles have less than desired aerodynamic and aesthetic qualities because they must be large, generally 4 to 8 inches wide, to accommodate binocular vision. In congested traffic, conventional external rear view mirrors can pose a safety hazard to other vehicles, such as bicycles and motorcycles, unless they fold upon impact (as is required in some countries). Small convex mirrors can be used externally to provide a wide field of view with direct viewing. Such mirrors are poor stand-alone rear viewing devices, however, because they create image distortion and present considerable difficulty in estimating distances.
Active systems, such as remote cameras and other electronic viewing systems, tend to have limited dynamic range of light intensities and poor binocular viewing capability. Such systems provide indirect viewing and require eye adaptation by the viewer from far to near vision. Active systems also tend to be too expensive for widespread automotive use. Thus, there is a need for a low cost automotive rear view mirror system that provides undistorted direct viewing with an acceptable field of view using a small optical element mounted externally and close to the body of the vehicle.